Passivehouse Calculations

[CC Chiang]

Hello,

I'm looking to see if there has been any updates to the EN673/ISO10077 workflow described on the page below:

https://windows.lbl.gov/en-673-iso-10077-using-window-and-therm-en-673-iso-10077-calculations

As you guys know, this is a rather convoluted process that requires modeling every system twice - once with a calibration panel and a second twice with the actual glazing. As the page was last updated in 2019, I wonder if this process is still valid or if advancements since have rendered it obsolete.

I'm starting on a Passivehouse analysis of a curtain wall system and ISO 10077 is the calculation standard for Passivehouse - even though it isn't curtain wall specific. If anyone has experience with Passivehouse modeling in LBNL, I'm all ears. Thanks!

[CC Chiang]

Hi,

Just wondering if LBNL folks have an answer to this. Thanks!

[D. Charlie Curcija]

Hi,

No changes as far as we know. Unfortunately, PassiveHous uses EN process, which involves calculation of linear thermal transmittance. We do provide open source engine for WINDOW, which includes EN method, and also have python implementation of the API to the engine, so one could make a python script that automates EWN process. 

Charlie

--
You can view the THERM forum online at:
https://groups.google.com/g/LBNL-THERM
---
You received this message because you are subscribed to the Google Groups "THERM" group.
To unsubscribe from this group and stop receiving emails from it, send an email to LBNL-THERM+...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/1b7bd10d-21e1-4072-ab42-fa51d85e7467n%40googlegroups.com.

--

-------------------------------------------------------------------------------------------

D. Charlie Curcija, Ph.D.                              Tel: (510) 495-2602

Lawrence Berkeley National Laboratory         Fax: (510) 486-4089

Windows & Envelope Materials Group           Cell:(510) 604-8668

1 Cyclotron Rd., 90R3147                           Email: dccu...@lbl.gov

Berkeley, CA 94720                                    Web: http://windows.lbl.gov/

-------------------------------------------------------------------------------------------

[CC Chiang]

Hi Charlie,

Thank you for the reply!

Is the open source engine for WINDOW the procedure described on this page?

A related question: I've seen European colleagues perform thermal modeling in THERM per EN 10077 without using calibration panels or COG U-values from WINDOW. Rather, a fixed value of 0.05 or 0.1 is assumed for insulated glazing (Triple and double) and a single THERM model is created. The psi value equations still apply, but they don't perform the calibration panel calculations. This was the main prompt for my question on the Google group. If one can perform EN 10077 calculations using this simplified procedure, is there still a reason to use the longer workflow on the LBNL EN673/ISO10077 page?

This is all assuming these colleagues are doing things correctly - as far as I can tell, all their contemporaries work the same way. But I wanted to check with the software creators at LBNL to see if there's any advisory on EN 10077 modeling.

Best,

Best Regards,
CC Chiang

[D. Charlie Curcija]

Hi CC,

Our programmer will send you a link for the python script and open source engine (pyWinCalc).

I haven' heard about this simplified approach, so I cannot be of help there. I would be skeptical that something not described in standard is allowed.

Charlie

[CC Chiang]

Hello Charlie,

Thank you! Look forward to the script and engine.

Hope you have a great weekend.

Best,

--

Best Regards,
CC Chiang

[Stephen Czarnecki]

Hi all

Here is a link to the python library: https://github.com/LBNL-ETA/pywincalc

I am not familiar with the procedure you are discussing so you may
have to evaluate how useful it may be. However since you are
discussing calculations involving the EN standard please note that
currently only ISO 15099 thermal calculations are supported at the
pywincalc level:
https://github.com/LBNL-ETA/pywincalc#Thermal-Calculations

There is also a calculation engine library that is used by pywincalc
which does have an implementation of the EN 673 thermal model:
https://github.com/LBNL-ETA/windows-calcengine. But that is currently
only available in C++ so using it may be a bit more complicated than
the pywincalc python library.

Thanks

Stephen

> To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/CA%2B%3Dswpi0RPJPpKyB5S6Ek045xZrB%3DHEWuVvCNMChHtOcxDOHJg%40mail.gmail.com.